The Notorious 1.4 CAVD twin charge... a story

[vorleys1982]

Hello, are we sitting comfortably?.....good, then I'll begin.

Back in 2016 I bought, on finance, a rather gorgeous 2010 VW golf 1.4 TSI in silver. By gorgeous I mean low KM's, barely a mark inside or out and not even a kerb scratch on the alloy wheels. It had full service history and only 1 owner. I test drove it and went back days later to pick it up.

Less than two weeks later the car had developed a rough idle and was bellowing thick dark smoke out of the back with a massive drop in power. I took it back to the dealership, after a couple of days and a courtesy car it was diagnosed with piston failure. In my doey eyed desire for the car I had not done enough home work and missed this apparently common fault with this particular engine. No problem, all covered under statutory warranty (I had purchased a 5 year warranty as well.).

For the next 12 months, I had no issue until one day sitting at a set of lights I felt a slight 'wobble'. I lifted the bonnet when I got back home and noticed the engine vibrating more than was normal. I kept an eye on it and mentioned it to the mechanic when I next took it for a service. He mentioned that it had multiple error codes (no engine light at this stage) the dump valve was faulty and the 'wobble' was a possible piston failure symptom.

I was pretty upset and went back to the dealership to discover my 'warranty' wasn't valid. Even if I had read the small print and got my car serviced at the dealership (not mentioned at time of purchase, but my fault I guess) the dealership had claimed the maximum amount to pay for the replacement first engine despite it falling well within the statutory 30 days and so they wouldn't pay any more money for engine parts.

So I decided to go for a second opinion. I'm not a mechanic, but I am an enthusiastic amateur, I have been pulling car engines apart for as long as I can remember. When piston rings or pistons fail, it is usually pretty catastrophic. You don't sit there straining to hear/feel a symptom and say 'can you hear that?'. You would usually say something like 'What the f**k was that??!?!' as something goes bang. So I thought that it couldn't be the piston or rings as it hadn't gotten any worse, there was no smoke and no dramatic loss of power.

So I kept driving for a few weeks. During which time the car developed a very loud squeal which turned out to be a fan belt pulley.

So I went to a VW dealership. The experts right? pay a premium to get a premium service right? Not on this occasion. The fan belt pulley was replaced and the noise gone, but the other symptoms remained. I drove home from the dealership which wasn't far from my house and popped the bonnet. What I saw I can only describe as a pretty poor show. several plastic brackets and holders were snapped and broken, a bolt that connects the engine mount to the engine was hanging out of the block, two other engine mount bolts were missing several hoses were disconnected and other bolts and bits were generally missing or in the wrong place.

So I went back. I complained (politely) that the original problem hadn't been diagnosed and there was all this damage. As a 'gesture of goodwill' they offered a free diagnosis. Fair enough, however when I asked about replacing the damaged parts I was flatly told no. Annoyed I decided to email VW head office and supplied pictures as well. Long story short 5 I was effectively told 'We're not fixing it. Go to trading standards if you don't like it' and they terminated contact.

So by this point I was at 'f**k it. I'm just going to drive it till it breaks.'. I still owed 3.5 years finance on it and I was pretty upset. The fan belt pulley repair was over $400 alone never mind the diagnostic fees etc.

Fast forward 18 months. The car has now developed a new fault; a drop in power, excessive fuel use and sooty plugs. combined with this was an engine light and occasional misfire. 'the beginning of the end' I thought.

So I took it to another VW dealership who confirmed my fears. 'I'm sorry sir, but we put a borescope into the cylinder bore and the piston is cracked. the car is on its last legs. That'll be $178.00'. Definitive right?

Then one day I noticed water underneath the car. the water pump was leaking, bad. long story short; I replaced it myself which was not an easy fix. The repair was like trying to redecorate your house from the outside through the bathroom window. The water pump is driven by the fan belt, no surprises there, but for the uninitiated the supercharger is driven by the water pump via a pully and an electromagnetic clutch. This is buried in the darkest deepest depths of the engine bay and that is the reason that it costs quite a bit to repair/replace and why some mechanics go slightly mad.

During this repair however I discovered several more things. Apart from the fact that previous mechanics had used a hammer to try and fix parts of it I found several damaged wires connected to one of the 3 MAF sensors. 'Hmmm' I thought, so one auto electrician (and $150) later this was repaired and the car took on a whole new persona, it regained its mojo, but it was short lived. After while it developed a misfire that would cause the car to stall and would sometimes go into limp home mode.

So on a whim I decided to go back to the original VW dealership and see it that 'Goodwill' was still there. It was, kind of... I spoke to a very lovely woman who could see my frustration and how upset I was a promised me faithfully to treat the car as if it were her own. Half a day later she called me, the news wasn't good. They had run a compression test and cylinder 2 was down. So between that and the 'borescope' comment it seemed terminal. I asked if it was the dreaded piston failure and the chief mechanic explained that it could be a number of things but didn't rule it out. Another $178.00.

Next I called my expert mechanic (my Dad) and explained my frustration. He's in the UK so can't here to help me. He said that a lot of the symptoms sounded like a damaged head gasket. The idea that you always get oil in the water making a creamy mess at the oil filler cap or the 'white smoke' coming out of the exhaust is a bit of a myth. These are just two of many many possible symptoms of a failed head gasket. So I tried some Steel Seal as a last resort. Didn't work.

'That's it!' I exclaimed to a friend over the phone. 'I've had enough!'. By this stage Covid had hit and I had lost my job so I was in no position to pay for repairs. So I limped it around until I got a new job that happened to come with a car. (A Hyundai I 20 - side note: this is a car with a surprising amount of power....none.) Then I resolved to pull the Golf to pieces and see once and for all what the issue was. If it was repairable, I would, if it wasn't I was going to dismantle it piece by piece and sell & post it around the country until it was gone...F**k this car!!!.

So I did. I took the cylinder head off. Incidentally, this is a lot harder than it sounds. I have replaced several cylinder head gaskets over the years, it is pretty straightforward. But it takes a lot of time which is why it will cost north of $3000 to replace a part that costs $200. So 2 weekends (2 full days worth of actual work), 3 skinned knuckles and a headache later, there it was! Not one, but three different problems!

Problem 1 - The wiring repair to the MAF sensor had broken again causing the over fuelling issue again
Problem 2 - Cylinder head gasket is in a pretty shocking state with obvious 'blow past'
Problem 3 - A damaged exhaust valve that needs relapping.

The timing chain had more play than a gamers convention so that's getting the treatment as well and is it just me or are VW ignition coils specifically designed to get brittle and break when you try and take them out??

Needless to say that if you have stuck with my story this far you will have drawn several conclusions... firstly; I'm an idiot. I didn't do my homework before buying the car and I didn't read the fine print on the warranty. Secondly, even highly paid mechanics working for the brand can be lazy too. Imagine if I had decided to scrap the car based on this diagnosis.... finally, if you learn anything from this story it is for the love of all that you hold holy don't buy the CAVD engine and if you do, be prepared for challenges.

Don't get me wrong, when it works well it gives most hot hatches a run for their money. It isn't GTi quick, but for a family hatch it is a belter. Long journeys are a breeze and it is comfortable and easy to drive, but it is an engine that is fraught with issues not least the dreaded piston ring failure, but if you encounter the same issues I've had then it can be extremely expensive to fix. This is why VW quietly discontinued it and it's variants.

So I am now waiting on a couple of parts and for the head to come back from a specialist reconditioning company and then I will clean and rebuild the engine. Overall based on estimates from several garages the cost would have been approx. $3500 to repair the head and replace the timing chain. As I'm doing it myself, including a few specialist tools I've had to buy, it will be approx. $900 all up.

If you've enjoyed this story, please comment and ask questions, this is a simplified version of the whole story and there is more, but probably even more boring. Also if anyone wants I will post up the reassembly of the engine as well with pictures.

Thanks for reading!

[kamold]

I applaud your can-do attitude despite your obviously sub-par situation and treatment.
It's a shame that what on paper sounds like a great engine has turned out to be one of their worst (and coupled with the DQ200 possibly the worst drivetrain combination ever to have come out of Wolfsburg).

[tigger73]

Hats off to you for taking it so far and also not taking the diagnosis being presented and doing your own investigation.

Be interested to know how many km you have on the engine at various points in time.

I think most people when they realise the POS they have bought either decide to fix it and flick it OR drive it until it dies.

[vorleys1982]

Hats off to you for taking it so far and also not taking the diagnosis being presented and doing your own investigation.

Be interested to know how many km you have on the engine at various points in time.

I think most people when they realise the POS they have bought either decide to fix it and flick it OR drive it until it dies.

So the KM's on the car when I bought it were approx. 86,000 when the original engine carked it. The engine that was put in after that I was told had 40,000 on it. Since looking at the timing chain, I call BS on that so the actual KM's on this engine are unknown, but if I was a betting man I'd put money on 160,000ish. The Odometer now reads 138,000 so its not like I've been piling the KM's on.

Also as a side note I've only ever run it on 98 and only from BP, Caltex or Shell. But its obviously impossible to know what the previous owner (and previous owner of the newer engine) ran the car on.

[vorleys1982]

Thanks for the encouragement. I'll follow up with the rebuild when i get through that. It'll be a few weeks, but I'll include more detail and pictures in that post.

Cheers

[tigger73]

So the KM's on the car when I bought it were approx. 86,000 when the original engine carked it. The engine that was put in after that I was told had 40,000 on it. Since looking at the timing chain, I call BS on that so the actual KM's on this engine are unknown, but if I was a betting man I'd put money on 160,000ish. The Odometer now reads 138,000 so its not like I've been piling the KM's on.

Also as a side note I've only ever run it on 98 and only from BP, Caltex or Shell. But its obviously impossible to know what the previous owner (and previous owner of the newer engine) ran the car on.

Yeah those km are pretty typical of others that have had issues. There's a good write-up on here with some theories on how emissions strategies employed on these cars (cold start cycle/heating cats) is destroying these engines faster. If/when you do get your car back together then getting the engine re-mapped and the cold start operation modified will be the best thing for longevity (unless you just decide to flog it off).

[h100vw]

Solid effort mate. If you need manuals please ask me.

Side note, not Vorleys, I wonder how many of these engines would have survived longer with better treatment. Not saying everyone doesnt look after them. Even when they come with history you've no idea how they were treated.

Many folk would have come from corollas and civics. Which would get to the moon on 91. Where the golf just cant tolerate it.

Gavin

[The_Hawk]

Welcome, and WOW! That's some nice work on your part on that engine! I hope you get it back together and working well, as you said, they really are a beautiful engine right up until they aren't

There's a good write-up on here with some theories on how emissions strategies employed on these cars (cold start cycle/heating cats) is destroying these engines faster. If/when you do get your car back together then getting the engine re-mapped and the cold start operation modified will be the best thing for longevity (unless you just decide to flog it off).

I wonder how many of these engines would have survived longer with better treatment. Not saying everyone doesnt look after them. Even when they come with history you've no idea how they were treated.

Many folk would have come from corollas and civics. Which would get to the moon on 91. Where the golf just cant tolerate it.

I bought mine new, only fed it 98 from day one, serviced it every 12 months (despite very low KMs) and had it tuned not long after I bought it. Even in 2011 I was aware of the issues that plagued the twincharger, but there was hope that revisions made in mid 2011 would help the problems and a tune apparently addressed many of the theoretical issues... although it's fair to say it was (and mostly still is) all guess work on why these engines all seem to go pop at some stage.

So despite the best of care, at just under six years old and only 31,000 on the clock cylinder two lost compression due to a crack. I was fortunate enough that VW came to the party and repaired it under goodwill (which was awesome) and 3.5 years later it's still running as well as it ever was and I still love it.

As suggested, a tune really wakes the engine up and addresses some of the theorised issues. It's worth doing some reading on some of the performance builds that have happened around the world too (although based on what you have written I suspect you may have read a thing or two ). There are plenty of things that are worth doing while it's all apart and plenty of stronger options (like forged pistons) to consider for longevity.


For my car, I'm not planning on replacing it any time soon and being the Cabriolet it's a little special anyway. Assuming it fails again one day in the future I'm left with a few options other than scraping it, which would be a real shame.

With my own money I couldn't put another twincharger into it knowing it's not fixing the underlying issues. Maybe if you were doing it yourself and were happy enough to rebuild it every five years or so... but otherwise, no.

Which leaves me with two options; GTI or full EV conversion.

The GTI conversion is theoretically the most straight forward since it's (again theoretically) a drop in replacement plus a little coding. A Stage 1 tune on a good GTI motor and a MQ350 gearbox would make for a nice upgrade too.

Lately, the idea of an EV picks away at the back of my mind. The reality is that I don't drive the car very far or very often so EV would be very practical, although I would probably be giving up any suggestion of interstate trips in this one if I went electric. It's also a second car so there is always something to move the family around. Having solar means I can charge it for FREE!!

Having a quick poke around there are kits out there, although most seem to be focussed on older cars, presumably it's easier to deal with the electrics in an old beetle But there are options for newer cars, for example:

VW / AUDI EV Conversion Kit Tesla Cells + HyPer 9 Motor | EVolution Australia
Electric Conversions | Oz Diy Electric Vehicles

Mind you, pricing seems to be easily $20k+ making the petrol alternative much more attractive... unless of course some EV conversion shop wants to sponsor the forum by doing the conversion as an advertising/partnership piece... ahhhh, if only! But I can dream right? For now at least, my twincharger seems to be pumping out the kW happily

[Nolan]

Which leaves me with two options; GTI or full EV conversion.The GTI conversion is theoretically the most straight forward since it's (again theoretically) a drop in replacement plus a little coding. A Stage 1 tune on a good GTI motor and a MQ350 gearbox would make for a nice upgrade too.Lately, the idea of an EV picks away at the back of my mind. The reality is that I don't drive the car very far or very often so EV would be very practical, although I would probably be giving up any suggestion of interstate trips in this one if I went electric. It's also a second car so there is always something to move the family around. Having solar means I can charge it for FREE!!

I've thought about the GTI swap too as a GTI wagon would be pretty special I think. I know in theory it should be easy but do you know of any swaps done in australia? Worried about costs and compliance. Mine is still going fine with no issues but I've hardly put any miles on it due to working from home.

[The_Hawk]

The reality is that the cost of a GTI replacement is probably more than the car is worth and especially for something that is "just another Golf" why bother? I'd suggest most people just throw a reco engine in and sell it or write it off as a loss

In theory, compliance shouldn't be an issue since the GTI is available in that chassis anyway... but again, no firm information.

[allagras]

Great story. I wasn't familiar with the CAVD but from your description, and the pics, sounds like its v similar to the CAXA engine i'm dealing with right now, but you get the added pleasure of trying to dig out the S/charger from the arse end of the engine bay.

Will look forward to hearing how the rebuild goes - and you've encouraged me to post my pics from the ffront end strip down of the wife's CAXA.

Good Luck
Grant

[vorleys1982]

Sorry for not getting this posted up sooner but life gets in way.
So after a few weekends of graft (and a few more spare parts) she’s back together and running and running well I might add.



Overall I spent more on parts (and tools) than originally anticipated, but that was mostly to ensure I was doing right by the car and the next owner.

The biggest task (and expense) was having the cylinder head reworked. I had a professional skim and re-machine the head, replace the damaged valve and clean an reseat the rest and I have to say the work he did was phenomenal. Brisbane Cylinder Head Service in Tingalpa if you are interested. He’s about 100 years old and you can tell he’s done this and only this for many years, not greatly communicative, but his work speaks for itself as you can see from the before and after.

Spare parts – beyond the obvious there were a few other parts I replaced, some necessary and some perhaps not.
Cylinder head refurb $650
Gasket Kit – $190
Cylinder head stretch bolts - $65
Timing Kit - $245
3 x MAF sensors - $180
4 Spark Plugs - $110 (yes really!)
4 ignition coils - $120
Air filter - $30
Oil filter $25
Oil $50
Wiring loom from similar model VW - $120 inc. postage from UK
Tools – I bought torque wrenches to make sure everything was done up correctly and the three sizes ¾, ½, ³/₈ inch drives came to approx. $200 but I have them forever more.

Timing/locking tool – This was the only part I would suggest shopping about and perhaps getting a cheaper version of. Mine came from China and included a pin for holding the hydraulic tensioner, the special tool for locking the camshafts in place, the bolt for holding the crankshaft in place and a (surprisingly) accurate gauge to identify TDC, I was very happy with it, but it is specific to the engine so can’t really use that anywhere else that came in at $75 - bargin.

Breaker bar – I bought a breaker bar that is massive. 750mm and solid steel and a chrome finish. Approx. $60 and worth every cent! There are bolts and other applications (holding things still whilst torqueing bolts) that this thing came into it’s own for!

So what did this odyssey into this engine show me? So not only was the exhaust valve charred about ¹/₃ of the way up the stem and not closing properly it was also cracked (almost completely through) I don’t think it would have lasted much longer.

Between the duff MAF sensor connector and the valve there was a lot of Sooting in the engine as well. Whilst the Loom was off the engine, I got a friend who repairs electronics equipment for a living to remove the faulty MAF plug and replace it with the one from the second hand wiring Loom (gotta love solder and heat shrink). Incidentally trying to get my hands on a second had Loom here was very very difficult, hence why it came from the UK (thanks Dad).

If you have faulty wiring/plugs in your Loom, this is my recommended fix as I have found that repair kits from VW and aftermarket plugs are not well made and rarely fit (this is the third repair to this plug ($150 & $120 respectively for each previous repair).

Reassembly was reversal (almost) of Disassembly. Putting the head back in place was a day in itself. First was assembly of the head. The spacer/injection rail which is a single complete unit had been removed for the refurb and the injectors numbered and given back separately. I could have replaced these as well, but they cleaned up nicely in some brake cleaner and the replacements would have been $500 +

CONT....

[vorleys1982]

CONT....



(left: injectors back in the head. Right: spacer/fuel injection rail reattached)

This engine relies on hydraulic lifters as part of the mechanism and the guy who did the refurb also gave me these back separately as well. He also taught me that they need to be bled before re assembly so that they don’t make the valves stick out when tightening down the cam cover. This is done using a suitable thin narrow tool, in my case a paperclip and then whilst applying a small amount of pressure to the lifter you move the tool around until you open the one-way valve and the oil is released. This was a great tip.

Then I cleaned the block mating surface with a craft knife blade and a plastic non scratch scouring pad and then vacuumed (several times) the bores and channels to make sure no nasty debris was in there. It is very important to not use harsh abrasives or scratch the mating surfaces in anyway.
With the head in place, I then tightened it down to the correct torque (30nm, then 90degrees, 90 degrees and a final 90 degrees) every engine will be different and there is also a correct order to do this in so please if you decide to do any head work yourself please consult the correct manual.

The hardest part was reconnecting the exhaust. To ‘make life easier’ in the beginning I decided to not remove the turbo or the manifold and leave it all in place and move it away, this turned out to be a real bind later. I did watch some videos of how the pro’s do this and there are literally 6 bolts holding on the front of the car, they remove these, disconnect the wiring loom for the lighting, Then the cooler, aircon and water pipes and the whole lot come off in one (by the looks, a professional can do this in approx. 1 hour.
Needless to say, I am missing a significant amount of skin from my knuckles as a result of my decision. I also used an exhaust putty to make sure there was a good strong seal and a new gasket.

Then the cams. In the timing kit there were replacement cogs for the cams (intake manifold is a left-hand thread so watch out if you do this yourself) the chain was about 8mm longer than the new one (note that VW consider this a non-serviceable part i.e. it will never need replacing within the lifetime of the car), they do stretch over time and while this one wasn’t in the danger zone, it does suggest that my assessment about how many KM’s this engine has done is probably correct.

After the head went in, I replaced the hydraulic lifters and put the cam cover on, this took several attempts as it is easy to knock the lifters out of place and then they do not line up and you have to start again. I also drenched these in oil prior to assembly.
Once this was sealed and bolted down the rest was pretty straight forward. The timing chain and tensioner went in smoothly, the gasket kit had a replacement oil seal and timing cover gasket which I sealed and bolted in.

(new cogs, timing chain, guide runners and hydraulic tensioner)

The engine mount was easy enough (breaker bar came in handy here).
The loom was a bit of a challenge as it needs routing and laying down in a particular order with the components that go in as well e.g. the MAF sensor wiring goes under the intake manifold, so when I put that in the wrong place, the manifold had to come back off and the wiring re laid.

I also (where access was possible) replaced the hose fittings with screw fit hose clamps (Jubilee clips). The VW hose clamps are a massive pain in the arse to remove without the special VW tool which is too expensive and unnecessary. I would recommend this as the replacement clamps are cheaper than the special tool, easier to work with and in my experience, make for a more reliable seal.

After this, there was the inaugural test firing. (note. that hydraulic lifers are very loud and crunchy when they don’t have oil in them). It didn’t fire first time, but the second time it fired and then got much quieter as the oil filled the lifters and channels etc. I was very very happy.

OBD2 reader shows no error codes so the electronic repairs have obviously worked and when driving, it seems to have got its Mojo back.
All up (including tools) I’m out a little over $2k. I could have saved $650 with parts that didn’t really need replacing (timing kit, coil packs etc. but it wouldn’t be doing the right thing for the next owner.

It also took a significant amount of time. I’m lucky in that I have access to another car, all up I would say there was close to 60 hours into this engine (hence why the quotes for a garage doing it were so high)

I also did some tidying up e.g. I replaced the expansion tank as it was discoloured and dirty, it was only $35 and it made a big difference after I cleaned the rest of the engine bay. Next is to clean, photograph and sell this car and hopefully the next owner will have years of trouble-free motoring.

Thanks for reading and the comments and messages of support. If anyone else is tackling something similar, please feel free to contact me and I’ll offer any advice I can to help.

[vorleys1982]

Great story. I wasn't familiar with the CAVD but from your description, and the pics, sounds like its v similar to the CAXA engine i'm dealing with right now, but you get the added pleasure of trying to dig out the S/charger from the arse end of the engine bay.

Will look forward to hearing how the rebuild goes - and you've encouraged me to post my pics from the ffront end strip down of the wife's CAXA.

Good Luck
Grant

Luckily I didn't have to take the supercharger off. The plastic cover that sits over the supercharger however.... I'm pretty sure it was designed by Satan himself or at the very least used in 'enhanced interrogation' in Guantanamo.

Let me know how you go with your rebuild. Yes I'm pretty sure the CAXA is of the same lineage. I did read an interesting article on the web somewhere of people replacing the CAVD with a CAXA to deal with the piston issue. I don't know how that would work out as i'm sure there are enough significant differences to mean this would need a EMS update of some description.

What is the issue with your wife's engine? Please post some picture of your rebuild as well.

Good luck

[Lucas_R]

Cracking effort mate - a well deserved pat on the back. I am pretty reasonable with mechanical knowledge and ability but would not have attempted a task this big. Glad to hear its running well which is a testament to your hard work and dedication.

Congrats.